The paper presents theoretical and experimental investigations of the structure of the spatial distributions of strain
amplitudes for an oscillating surface using an optical interferometer. A conventional Michelson interferometer and
an interferometer containing an acousto-optic cell have been studied. It has been shown that the maximum possible sensitivity of the device is 0.001 &angst;, with the minimum strain amplitude reaching 0.001 &angst;. Practical advantages of the interferometer with an acousto-optical cell have been realized.